OBD Guide

P1303

Cylinder Number 3 Random Misfire Detected

P1303 is an OBD-II diagnostic trouble code meaning: Cylinder Number 3 Random Misfire Detected. Common causes: spark plug fault in cylinder 3, problems with the ignition coil. Estimated repair cost: $6–56.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–56 (est.)

Symptoms

  • The engine hesitates or runs rough
  • Reduced engine power
  • Increased fuel consumption
  • Check Engine light is on
  • Engine vibrations at idle

Causes

  • Spark plug fault in cylinder 3
  • Problems with the ignition coil
  • Clogged or faulty fuel injector
  • Low cylinder compression
  • Problems with the ignition system wiring harness

How to Fix

  1. Check and replace spark plug in cylinder 3
  2. Check the functionality of the ignition coil
  3. Check and replace fuel injector if necessary
  4. Measure the compression in the cylinder
  5. Check the condition of the ignition system wiring harness

Related codes

Error P1303 by Vehicle Brand

FAQ

What does the P1303 code mean?

P1303 is an OBD-II diagnostic trouble code that indicates: Cylinder Number 3 Random Misfire Detected

What causes a P1303 error code?

The most common causes of P1303 include: Spark plug fault in cylinder 3; Problems with the ignition coil; Clogged or faulty fuel injector; Low cylinder compression.

How do I fix a P1303 diagnostic trouble code?

To fix P1303: Check and replace spark plug in cylinder 3. Check the functionality of the ignition coil. Check and replace fuel injector if necessary. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1303?

Limited driving only, diagnose soon

How much does it cost to fix P1303?

The estimated repair cost for P1303 is $6–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat